Abstract Using techniques developed by Hamkins, Reitz and the second author, we determine the modal logic of inner models.

Alessandra Carbone, Fernando Ferreira, Benedikt Löwe, Elvira Mayordomo; Computability in Europe 2010, Journal of Logic and Computation, Volume 25, Issue 4,

Abstract We work under the assumption of the Axiom of Determinacy and associate a measure to each cardinal κ < ℵ ε0 in a recursive definition of a canonical measure assignment. We give algorithmic applications of the existence of such a canonical measure assignment (computation of cofinalities, computation of the Kleinberg sequences associated to the normal ultrafilters on all projective ordinals).

Klaus Ambos-Spies, Arnold Beckmann, Erzsébet Csuhaj-Varjú, Benedikt Löwe; Computability in Europe 2009, Journal of Logic and Computation, Volume 23, Issue

Arnold Beckmann, Benedikt Löwe; Computability in Europe 2008, Journal of Logic and Computation, Volume 22, Issue 2, 1 April 2012, Pages 163–164, https://do

The six papers in this special issue arose from the conference CiE 2009: Mathematical Theory and Computational Practice, held at the Ruprecht-Karls-Universitat Heidelberg, Germany, in July 2009. CiE 2009 was the fifth meeting in the series of conferences associated with the Association for Computability in Europe.

F. FerreiraDepartamento de Matematica, Faculdade de Ciencias, Universidade de Lisboa, Campo Grande,1749-016 Lisboa, Portugale-mail: [email protected]. Lowe ( )Institute for Logic, Language and Computation, Universiteit van Amsterdam, Postbus 94242,1090 GE Amsterdam, The Netherlandse-mail: [email protected]. LoweDepartment Mathematik, Universitat Hamburg, Bundesstrasse 55, 20146 Hamburg, GermanyE. MayordomoDepartamento de Informatica e Ingenieria de Sistemas, Instituto de Investigacion en Ingenieria deAragon (I3A), Universidad de Zaragoza, 50015 Zaragoza, Spaine-mail: [email protected]

In a recent paper, van Benthem, Gerbrandy, Hoshi and Pacuit gave a natural translation of dynamic epistemic logic (DEL) into epistemic temporal logic (ETL) and proved a representation theorem, characterizing those ETL models that are translations of some DEL protocol; among the characterizing properties we also find synchronicity. In this paper, we argue that synchronicity is not an inherent property of DEL, but rather of the translation that van Benthem et al. used. We provide a different translation that produces asynchronous ETL models and discuss a minimal temporal extension of DEL that removes the ambiguities between the possible translations. This allows us a first attempt at assessing which of the epistemic-temporal properties are intrinsic to DEL and which are properties of the translation.

interdisciplinary network Computability in Europe.Computability in Europe (CiE) used to be an informal network of European scientists working on computability theory, including its foundations, technical development, and applications-mainly identified by its successful conference series with

The 12 papers in this special issue arose from the conference CiE 2006: Logical Approaches to Computational Barriers, held at the University of Wales Swansea in July, 2006. CiE 2006 was the second of a new series of conferences associated with the interdisciplinary network Computability in Europe. Computability in Europe (CiE) is an informal network of European scientists working on computability theory, including its foundations, technical development and applications. Among the aims of the network is to advance our theoretical understanding of what can and cannot be computed, by any means of computation. Its scientific vision is broad: computations may be performed with discrete or continuous data by all kinds of algorithms, programs and machines. Computations may be made by experimenting with any sort of physical system obeying the laws of a physical theory such as Newtonian mechanics, quantum theory or relativity. Computations may be very general, depending upon the foundations of set theory; or very specific, using the combinatorics of finite structures. CiE also works on subjects intimately related to computation, especially theories of data and information, and methods for formal reasoning about computations. The sources of new ideas and methods include practical developments in areas such as neural networks, quantum computation, natural computation, molecular computation, computational learning. Applications are everywhere, especially, in algebra, analysis and geometry, or data types and programming.

We define a notion of combinatorial labellings, and show that Δ20 is the largest boldface pointclass in which every set admits a combinatorial labelling.

The ten papers in this special issue arose from the conference CiE 2005: New Computational Paradigms, held at the University of Amsterdam in June, 2005. CiE 2005 was the first of a new series of conferences associated with the interdisciplinary network Computability in Europe focused on computability in theoretical computer science and mathematical logic, and ranging over a broad spectrum of research areas from the application of novel approaches to computation, through computability-theoretic aspects of physical systems to set-theoretic analyses of infinitary computing models.

The author establishes a connection between Revision Theory of Truth and Infinite Time Turing Machines as developed by Hamkins and Kidder. The ideas from this paper have incited Welch to solve the limit rule problem of revision theory.

Abstract We give characterizations for the (in ZFC unprovable) sentences “Every -set is measurable” and “Every -set is measurable” for various notions of measurability derived from well-known forcing partial orderings.